I'm looking into buying the camaro ram airII hood.
It only works for the 90-92 speed density cars.

"What is the term speed density referring to?"

Is this a sensor?

 

Earlier cars use a MAF (Mass Air Flow) sensor. That system is technically superior, but far more poorly executed, than the later S/D system. The MAF system literally counts air molecules entering the engine in order to know how much fuel to meter, while the S/D tries to infer the number of air molecules by reading a bunch of other things. The earlier MAF cars were crippled by various features of the specific MAF they used, and the computer's handling of the data it generated; that's why in TPI, the S/D is the preferred setup. However almost all newer cars use a MAF, including the LS1 for instance, because it simply works better in every way when executed properly.

In any case, the MAF sensor itself is in the intake ducting ahead of the throttle body, and apparently interferes with that particular hood. The S/D cars don't have it.